Some conventional data networks use virtual links. For example, ARINC 664 part 7 defines a profiled Ethernet that allows analyzing traffic flows between endpoints of a full-duplex switched Ethernet network with respect to transmission timing. At the Ethernet network level a virtual link is realized by a locally administered multicast group with a network-wide unique multicast Ethernet address. That is all frames of a virtual link use the same Ethernet multicast destination address, whereas frames of different virtual links use different Ethernet multicast destination addresses. At the Ethernet network level, frames of a virtual link can thus be identified by their destination Ethernet addresses.